AVRO-3088: use modern CMake style with config file

[mitjap]

I'm proposing some changes to CMake that would also install config file which makes it easier for downstream libraries to use avro as dependency.

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Jira

• My PR addresses the following Avro Jira issues and references them in the PR title. For example, "AVRO-1234: My Avro PR"
  • https://issues.apache.org/jira/browse/AVRO-3088
  • In case you are adding a dependency, check if the license complies with the ASF 3rd Party License Policy.

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• My PR adds the following unit tests OR does not need testing for this extremely good reason:

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[mitjap]

This PR does two things, it uses more modern CMake with targets and better manages dependencies between targets and add installation of config files. Do you think this shuld be two separate PRs?

[mkmkme]

Hey @mitjap !

Are you still interested in getting this finalized?

[mitjap]

If I remember correctly this is it. I was waiting for a feedback before removing a draft label.

[mkmkme]

Okay, thanks!
I'll take a closer look as soon as possible.

If you could rebase it on the top of current main, it would be great.

[mkmkme]

Also if you could split it into two PRs as you suggested above, it would be much easier to review!

If you don't have time for doing this, let me know and I can do this myself